1. Field of the Invention
The present invention is generally related to a marine propeller and, more specifically, to a marine propeller that is particularly configured to improve the maximum velocity, acceleration, and cruise speed characteristics of a marine vessel used in conjunction with the marine propeller.
2. Description of the Related Art
Those skilled in the art of marine propellers design are familiar with many different combinations of characteristics of marine propellers that affect its performance under various conditions.
U.S. Pat. No. 3,788,267, which issued to Strong on Jan. 29, 1974, discloses an anti-cavitation means for marine propulsion devices. Cavitation emanating from the leading edge near the hub of a propeller of a marine propulsion device is prevented by introducing exhaust gas air adjacent the junction of the leading edge of each blade of the propeller and the propeller hub from the interior of the hub through which the exhaust gas or air flows.
U.S. Pat. No. 4,789,306, which issued to Vorus et al. on Dec. 6, 1988, describes a marine propeller. A multi-bladed marine propeller is designed for efficient operation in intermediate, partially cavitating flow regions between fully cavitating flow and non-cavitating flow. Each of the blades has a radially inner sub-cavitating section and an outer section which is configured to have a higher angle of attack and tapered trailing and leading edges so that it super cavitates at high speeds either with or without ventilation and subcavitates at lower speeds. Various other features of each blade include different length cords on the pressure and suction sides of the outer section and an inclined trailing surface area extending between the cord ends for improved off-design, design point, and stern operation.
U.S. Pat. No. 4,802,822, which issued to Gilgenbach et al. on Feb. 7, 1989, discloses a marine propeller with optimized performance blade contour. The propeller combines decreasing overall pitch from hub to blade tip and increasing progressiveness of pitch with increasing radii from hub to tip, and provides uniform loading from hub to tip. The blade has a maximum transverse dimension between the high pressure surface of the blade and a straight line chord between the leading edge and the trailing edge of the blade. The ratio of this maximum transverse dimension to the length of the chord is ever increasing from hub to tip. A parabolic blade rake along the maximum radial dimension line of the blade is provided in combination.
U.S. Pat. No. 4,865,520, which issued to Hetzel et al. on Sep. 12, 1989, discloses a marine propeller with an addendum. The propeller has a plurality of blades each with an integral addendum extending rearwardly from the trailing edge of the positive pressure surface of the blade. A particular combination of blade area ratio and blade rake is provided to enable quick acceleration to a high speed on plane condition in blade surfacing racing applications, and without bobbing up and down. The blade area ratio is at least 40 percent and the blade rake is 10 to 25 degrees.
U.S. Design Pat. D319,210, which issued to Koepsel et al. on Aug. 20, 1991, discloses a five blade marine propeller.
U.S. Pat. No. 5,104,292, which issued to Koepsel et al. on Apr. 14, 1992, discloses a marine propeller with performance pitch, including a five blade version. The propeller combines progressive pitch with both increasing pitch and increasing progressiveness of pitch along at least a portion of increasing radii from the axis of rotation to the outer blade tip. A five blade propeller is provided which accommodates thermal warpage of the outer blade tips, such that the same propeller includes two different types of blades, one blade having increasing pitch with increasing radii all the way to the outer blade tip and the other type of blade having increasing pitch to a given radius and then decreasing pitch with increasing radii to the outer blade tip.
U.S. Pat. No. 5,114,313, which issued to Vorus on May 19, 1992, describes a base vented subcavitating marine propeller. The propeller consists of a central having a hollow body of circular cross-sectional shape through which exhaust gas from the motor can flow. Integrally formed with the hub are a number of arcuate blades. Each blade has a generally fish-shaped axial cross-sectional shape. In particular, from the leading edge of the blade, the cross-sectional shape increases in thickness until reaching a local maximum at a point near the midchord of the blade and thereafter decreases in thickness until reaching a local minimum.
U.S. Pat. No. 5,158,433, which issued to Cleary on Oct. 27, 1992, discloses a marine propeller having an outwardly flared hub. The propeller includes an inner hub to receive a driving connection to the engine and an outer hub which is spaced outwardly from the inner hub to provide a passage therebetween for the discharge of exhaust gas from the engine. After casting the trailing end of the outer hub is swaged outwardly by a tapered tool to provide an outwardly flared trailing end which assists gas flow and enhances performance of the engine.
U.S. Pat. No. 5,236,310, which issued to Koepsel et al. on Aug. 17, 1993, discloses a marine propeller with performance pitch, including a five blade version. The propeller combines progressive pitch with both increasing pitch and increasing progressiveness of pitch along at least a portion of increasing radii from the axis of rotation to the outer blade tip.
U.S. Pat. No. 5,368,508, which issued to Whittington on Nov. 29, 1994, describes a marine propeller with transversal converging ribs. The propeller includes arcuate ribs extending from each blade surface. Each rib is widely spaced at the blade's leading edge and curves inwardly towards the propeller hub to substantially converge at the blade's trailing edge.
U.S. Pat. No. 5,464,321, which issued to Williams et al. on Nov. 7, 1995, describes a marine propeller. The propeller uses the circulation control principal of blowing tangentially over a Coanda surface at the trailing edge of each blade to develop high blade lift. Each blade has internal chambers and two blowing slots so that blowing is controllable for forward and reverse thrust without reversing rotational direction of the propeller.
U.S. Design Pat. D368,886, which issued to Kuryliw on Apr. 16, 1996, describes a boat propeller.
U.S. Pat. No. 5,527,195, which issued to Neisen on Jun. 18, 1996, is discloses a flow through marine propeller. The propeller has an integral aft skirt portion, with a plurality of slots extending forwardly from the trailing end and dividing the skirt portion into a plurality of circumferentially spaced segments separated from each other at the trailing end by respective slots therebetween and integrally joined to each other at the outer hub forward of the slots.
U.S. Pat. No. 5,791,874, which issued to Lang on Aug. 11, 1998, discloses a marine propeller with adjustable cupping. The propeller includes a hub rotatable about a longitudinal axis and having a plurality of blades extending outwardly from the hub. Each of the propeller blades includes a fixed propeller blade stem and a removable cup extension.
U.S. Design Pat. D442,906, which issued to Prokop on May 29, 2001, describes a marine propeller with thrust edges.
U.S. Pat. No. 6,390,776, which issued to Gruenwald on May 21, 2002, discloses a marine propeller. It has increased performance in reverse gear and has a hub and a multiplicity of blades extending radially outward. A portion of the trailing edges of some or all of the blades are modified to lessen interference between blades and increase the bite of those blades when operated in reverse.
U.S. Pat. No. 6,699,016, which issued to Dean on Mar. 2, 2004, describes a boat propeller. The propeller is provided with a hub having a plurality of outwardly extending blades and at least one reverse thrust member connected to a selected blade of the propeller. The blade to which the reverse thrust member is connected can provide a blade pitch that is constant, variable, progressive, or regressive. The reverse thrust member is formed integrally with or connected to a leading edge of the selected blade.
U.S. Pat. No. 7,025,642, which issued to Baylor on Apr. 11, 2006, describes a boat propeller which includes a hub having a front, back, and an axis of revolution extending therebetween. A plurality of blades provides and extends from the hub between the front and back. Each blade includes a surface adjacent of the hub disposed at an oblique angle to the hub axis and a blade tip having an adjacent surface forming a dihedral angle with a surface adjacent to the hub extending on the forward camber only. The surface adjacent to the blade tip is inclined at a greater angle to the hub axis than the surface adjacent to the hub.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.